The Design of an Experimental System of Estimation Methods for Effects of Heavy Metals and their Mixtures on Daphnia Magna

A study was conducted with Daphnia magna Straus to design an experimental system of estimation methods for effects of heavy metals and their mixtures. Acute and chronic experiments with five heavy metals (Cu, Cr, Zn, Ni and Fe) as well as their mixtures were performed according to 96-h LC50 of separate metals and Maximal Permissible Concentrations (MPC). The prepared mixtures were taken as 100% solutions. Cu ions appeared to be of the highest acute toxicity to D. magna, followed by Cr, Zn, and Ni ions and Fe being the least toxic. D. magna's susceptibility to mixtures of heavy metals was considerably high: 96-h LC50 was 1.1% when the mixtures were prepared according to both LC50 for separate metals and MPC. Sublethal concentrations of heavy metals negatively affected the reproduction parameters of D. magna: egg deposition time, juvenile appearance, number, mortality and juvenile growth. The estimation system for effects of heavy metals and their mixtures was prepared based on experimental data design and other authors. publications.